.TH std::ranges::adjacent_view::size 3 "2024.06.10" "http://cppreference.com" "C++ Standard Libary"
.SH NAME
std::ranges::adjacent_view::size \- std::ranges::adjacent_view::size

.SH Synopsis
   constexpr auto size() requires ranges::sized_range<V>;              (since C++23)
   constexpr auto size() const requires ranges::sized_range<const V>;  (since C++23)

   Returns the number of elements.

   Let base_ be the underlying view. Equivalent to:

 using SizeType = decltype(ranges::size(base_));
 using CommonType = ranges::common_type_t<SizeType, std::size_t>;
 auto size = static_cast<CommonType>(ranges::size(base_));
 size -= std::min<CommonType>(size, N - 1);
 return static_cast<SizeType>(size);

.SH Parameters

   \fI(none)\fP

.SH Return value

   The number of elements, may be 0 if ranges::size(base_) is less than N.

.SH Example


// Run this code

 #include <ranges>

 int main()
 {
     constexpr static auto v = {1, 2, 3, 4, 5, 6};

     constexpr int width1 {4};
     constexpr auto view1 {std::views::adjacent<width1>(v)};
     static_assert(view1.size() == 3);
     static_assert(view1.size() == (v.size() - width1 + 1));

     constexpr int width2 {8};
     constexpr auto view2 {std::views::adjacent<width2>(v)};
     // window is too wide, so view2 has no elements:
     static_assert(view2.size() == 0);
 }

.SH See also

   ranges::size  returns an integer equal to the size of a range
   (C++20)       (customization point object)
   ranges::ssize returns a signed integer equal to the size of a range
   (C++20)       (customization point object)
